Diamond Inclusions

Diamond Inclusions is the first book ever published that is devoted entirely to inclusions; their size, position, quantity, type, color and how they affect the finished diamond. It covers not only external and internal characteristics but documents and tracks diamond inclusions from the rough crystal to the fully faceted gem product. Five rough gem diamonds ranging in size from 4.72cts to 17.58cts are documented in this manner. Additionally, diamond inclusions are further examined in a separate section on how they are affected during the sawing, bruting and polishing processes. It discusses how heat, pressure, friction, diamond powder and other mechanical areas that may affect certain types of diamond inclusions.

Diamond Inclusions the book is a resource for the gemologist, diamond grader, diamond dealer, retail jeweler and anyone that is related to the diamond industry.

The author Mr. Nizam Peters has spent over four years primarily photographing and documenting the varieties of diamond inclusions in this current work. He is the current author of several other books and the director of the American Institute of Diamond Cutting, Inc. An internationally recognized school dedicated to teaching the art of diamond cutting and rough diamond grading.

The natural seen in the pavilion of this diamond clearly displays the surface grain of the original rough crystal. (1.2)

1.3

Displayed on the pavilion point corners of this natural green blue emerald cut are two larger indented naturals. The right natural reveals obvious surface grain. (1.3)

B. Internal Characteristics

1. Features resulting from mineral type inclusions

(crystalline and solid) embedded in the body of the diamond

2. Features resulting from impurities that existed within and around the formation of the crystal

3. Features resulting from structural defects during and after the process of crystallization

4. Features resulting from the manufacturing process and excessive wear and tear

9.3

Examining the pavilion of this diamond from a side view, we can just discern a play of colors from reflected light within the included crystals.

9.4

This colorful photograph was captured when these included crystals were subjected to an intense light source, resulting in a strong play of bright colors. The included crystals were magnified at 70x. (9.4)

Rotating the rough diamond to the opposite octahedral face, we can clearly observe the two feather inclusions that were visible on the left side of photo 14.1b. Both of the feather inclusions are surface reaching, but did not create any cavities on the surface. Additionally, we can detect two pinpoint carbon inclusions that are close to the surface. At the right bottom edge of the octahedral face are displayed bright prismatic colors, which strongly suggest tension in that area of the rough. Both the pinpoint carbon and the tension-filled area have a high probability of being removed in the manufacturing process. (14.3b)

14.4b

At 22x magnification we can closely observe the tension-filled area that was seen in photo 14.3b. At the left and bottom we can inspect two well-shaped trigons. (14.4b)

D.The diamond manufacturing process and it relationship to inclusions

15.36

This feather inclusion ran parallel to the surface of the girdle. During bruting it cleaved, leaving a large cleavage break. Notice that part of the feather has penetrated under the surface of the girdle. (15.36)

b. Inclusions developing because of stress and strain

As discussed previously, stress and strain in a diamond is very often unseen and is only realized when an inclusion develops for no apparent reason. If detected by using the polariscope, the bruter will use more caution during bruting but this is quite beyond his control if inclusions do develop.

The forcing process that is used in bruting, if tension exist in one or more areas of the bruted surface, inclusions will suddenly develop due to the release of tension. The type of inclusions that develop are often feather type inclusions that trail from the bruted surface to varying depths internally. Sometimes as the brutting process continues, the inclusions can open or break away from the brutted surface creating pits, nicks and cavities.

c. Inclusions produced by the bruter

During the bruting process, the bruter can sometimes press the industrial too hard against the gem diamond that is being brutted and thereby create a rough girdle. A rough girdle is where minute feather inclusions develop that extend from girdle surface to microscopic short distances.

Table of Contents

External Features
External features can be divided into four general groups in which they occur in many different varieties and form.

1. Features that are primarily natural in origin (Chapters one thru four)
2. Features resulting from the manufacturing process (Chapter five and six)
3. Features resulting from wear and tear (Chapter seven)
4. Features that are both external and internal (Chapter eight)

CHAPTER One
Naturals,growth markings and radiation stains.

CHAPTER TWO
External grainings, twinning lines and knots.

CHAPTER THREE
Cavity, pits and nicks.

CHAPTER FOUR
Surface hairline feathers, cleavage and fracture breaks close to the surface.

INTERNAL FEATURES
Internal features can occur in many different varieties and shapes. They can be classified into four general categories.

1. Features resulting from mineral type inclusions (crystalline and solid) imbedded in the body of the diamond (Chapter nine)
2. Features resulting from impurities that existed within and around the formation of the crystal (Chapter 10)
3. Features resulting from structural defects during and after the process of crystallization (Chapter eleven and twelve)
4. Features resulting from the manufacturing process and excessive wear and tear (Chapter thirteen)

CHAPTER FIFTEEN
1. The diamond manufacturing process and its relation to inclusions.
2. Planning the rough in relation to shape and inclusions.
3. Sawing the rough with consideration to inclusions.
4. Bruting the rough in relation to inclusions.
5. Cutting and polishing the rough with regard to inclusions.

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